Obesity is characterized by a number of cardiovascular alterations, and whether these alterations involve arterial compliance is unknown. In 12 young, obese, normotensive subjects (age, 23.9±1.3 years; mean±SEM) and 12 age- and sex-matched lean control subjects we measured blood pressure, radial artery diameter, and radial artery compliance continuously over the systodiastolic pressure range with a Finapres device and recently developed echo-tracking device. Measurements were obtained at baseline and after prolonged ischemia, that is, when diameter and compliance are increased. Blood pressure values were normal in both groups (obese subjects: 109.2±4.9/68.2±2.7 mm Hg; lean control subjects: 108.2±4.1/60.7±3.8 mm Hg), but in addition to a marked increase in body mass index (38.5±0.8 versus 23.1±0.9 kg/m2, P<.01), obese subjects showed a slight and nonsignificant increase in heart rate (71.1±3.2 versus 66.7±3.3 beats per minute, P=NS), increases in left ventricular wall thickness and left ventricular mass index (121.5±4.8 versus 103.4±3.3 kg/m2, P<.01), no changes in plasma renin activity and plasma norepinephrine (compared with normal values), and a marked reduction in total body glucose uptake (glucose clamp technique). Obese subjects showed radial artery diameter and compliance values that were greater than those seen in control subjects throughout the systodiastolic pressure range. The differences were 13% (P<.05) and 96% (P<.01), respectively, and both diameter and compliance remained higher in obese than lean subjects after forearm ischemia. In obese and lean subjects baseline radial artery diameter values correlated highly with body weight, body surface area, and body mass index. Thus, radial artery compliance is increased in young, obese, normotensive subjects. Whether these changes are related to functional factors or intravascular or extravascular structural changes remains to be determined. The increase, however, is similar to what has been described in mild essential hypertension, emphasizing the similarity of the cardiovascular alterations in these two conditions.
- cardiovascular system
- radial artery